000
FXUS63 KEAX 180817
AFDEAX
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
317 AM CDT Sun Mar 18 2018
.Discussion...
Issued at 318 AM CDT SUN MAR 18 2018
Water vapor imagery and 500mb heights shows an area of lower heights
with embedded shortwaves over the western quarter of the CONUS.
Satellite imagery also shows a plume of mid to upper level
moisture streaming into the Southern Plains from the Pacific.
850mb-700mb moisture transport vectors show that as one of the
western shortwaves moves into the Plains this evening, that it
draws this richer moisture into it. Models seem to have converged
on a solution that brings moderate rainfall to the area this
evening and overnight. The heaviest rain looks to be over the
southern half of the forecast area. Rain amounts in this area look
to be between half an inch and an inch. This will help with the
abnormally dry to moderate drought areas based on the latest US
Drought Monitor. There may also be some embedded thunderstorms,
mainly south of the Missouri River. Given low instability, no
severe or even strong storms are expected.
The other issue for today into Monday is temperatures. It looks like
clouds will linger longer than previously thought. And even if/when
the low clouds erode, it looks likely that higher level clouds will
be moving in. So for today, have lowered highs several degrees to
keep temperatures in the mid 40s north to the mid 50s south. For
tomorrow, highs may once again be too warm. But there is some
uncertainty as to how quickly clouds and rain move away from the
area. At the moment, it looks there could be some breaking up clouds
in the afternoon. The GFS and the ECMWF show this and then warm
highs into the middle 50s. The NAM and the Canadian linger clouds
and precipitation longer. There is also a fair amount of spread
on ensemble plume diagrams. Have lowered temperatures some to
bring highs on Monday to around 50. This seemed like a reasonable
compromise given the varying guidance.
The rest of the forecast looks quiet, until perhaps Thursday night.
There should be a general warming trend through the middle of the
week and by Thursday highs should climb into the middle 60s.
Regarding rain chances Thursday night into the weekend, there is
a fair amount of spread in the models. The GFS is fastest, moving
a system across the area through this period of time. Initially,
it develops warm advection precipitation along what looks like a
warm front Thursday night into Friday. The ECMWF never develops
this warm advection precipitation and ultimately is slower with
the system, progressing it through several hundred miles behind
the GFS. For now, chance PoPs look reasonable Thursday night
through Saturday given the varying timing of the system among the
models.
&&
.Aviation...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1121 PM CDT SAT MAR 17 2018
MVFR CIGs are currently prevailing across the state line
terminals thanks to the moisture trapped under the nocturnal
inversion. Expect this to persist through the rest of the
overnight hours into late Sunday morning when easterly surface
winds might then help scatter out clouds. Otherwise, storms
forecast for Sunday evening look to move into the terminals after
the end of the TAF cycle.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Discussion...CDB
Aviation...Cutter